IGBT short circuit transient process junction temperature state evaluation method and device based on current drop rate

Abstract

The invention provides an IGBT short-circuit transient process junction temperature state evaluation method and device based on a current drop rate, and the method comprises the steps: obtaining an IGBT short-circuit current process waveform which comprises a rising stage, a continuous stage and a dropping stage; acquiring a control relation of the grid voltage to the collector current in the descending stage, and acquiring a relation between junction temperature and electron mobility in the ascending stage and the continuous stage; the relation between the current drop rate and the junction temperature change is obtained by combining the control relation of the grid voltage in the drop stage to the collector current and the relation between the junction temperature and the electron mobility in the rise stage; and evaluating the junction temperature state of the IGBT short circuit transient process based on the relationship between the current drop rate and the junction temperature change. By observing the change of the drop rate of the short-circuit current, the junction temperature change of the IGBT can be estimated in real time, instant temperature information is provided, and the state monitoring and analysis of the IGBT short-circuit process have guiding significance.

Description

Technical Field

[0001] The present invention relates to the technical field of IGBT junction temperature evaluation, and in particular to a method and device for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Insulated Gate Bipolar Transistor (IGBT) devices have the advantages of fast switching speed of MOSFET devices and low conduction loss of bipolar devices. They have been widely used in new energy converters, flexible DC transmission equipment, dynamic reactive power compensation equipment and other occasions.

[0004] The junction temperature (Tj) of an IGBT refers to the temperature of the semiconductor junction inside the IGBT. The junction temperature is a key parameter affecting the performance and reliability of the IGBT, because high junction temperature affects the electrical characteristics of the device and may cause it to fail prematurely. However, in the current existing technology, there is no effective method for estimating the junction temperature of the IGBT in the short-circuit state. Summary of the invention

[0005] In view of this, the present invention provides a method and device for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate, so as to solve at least one of the above-mentioned problems.

[0006] In order to achieve the above object, the present invention adopts the following scheme:

[0007] According to a first aspect of the present invention, there is provided a method for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate, the method comprising: obtaining an IGBT short-circuit current process waveform, the IGBT short-circuit current process waveform comprising a rising phase, a sustained phase and a falling phase; obtaining a control relationship between a gate voltage and a collector current in the falling phase; obtaining a relationship between junction temperature and electron mobility in the rising phase and the sustained phase; obtaining a relationship between a current drop rate and a junction temperature change based on the control relationship between the gate voltage and the collector current in the falling phase and the relationship between the junction temperature and electron mobility in the rising phase; and evaluating the junction temperature state of the IGBT short-circuit transient process based on the relationship between the current drop rate and the junction temperature change.

[0008] As an embodiment of the present invention, obtaining the waveform of the IGBT short-circuit current process in the above method includes: obtaining the waveforms of the gate voltage, the collector-emitter voltage and the collector current during the IGBT short-circuit process.

[0009] As an embodiment of the present invention, the control relationship between the gate voltage and the collector current in the falling stage of the above method is shown in the following formula:

[0010]

[0011] In the above formula, i C is the collector current; μ n is the electron mobility; α pnp is the transistor transport coefficient; w is the gate channel width; l is the gate channel length; c ox is the capacitance per unit area of ​​the gate channel; u GE is the gate voltage; U T is the gate threshold voltage.

[0012] As an embodiment of the present invention, the relationship between the junction temperature and the electron mobility in the rising stage of the above method is as follows:

[0013]

[0014] In the above formula, μ n is the electron mobility; T j is the junction temperature.

[0015] As an embodiment of the present invention, in the above method, the relationship between the current drop rate and the junction temperature change is obtained by combining the control relationship between the gate voltage and the collector current in the falling stage and the relationship between the junction temperature and the electron mobility in the rising stage, including:

[0016] The control relationship between the gate voltage and the collector current in the falling phase is derived by time derivative, and the following is obtained:

[0017]

[0018] Combining the time derivative formula and the relationship between the junction temperature and the electron mobility in the rising stage, the relationship between the current drop rate and the junction temperature change in the falling stage is obtained as follows:

[0019]

[0020] As an embodiment of the present invention, the method of evaluating the junction temperature state of the IGBT short-circuit transient process based on the relationship between the current drop rate and the junction temperature change includes:

[0021] At room temperature T env At 25℃, the waveform of the current drop is recorded as i C,env ;

[0022] At junction temperature T j When the current drops, the waveform is recorded as iC,Tj ;

[0023] Through the known T env 、i C,env 、i C,Tj The junction temperature T is estimated using the following equation based on the relationship between the current drop rate and the junction temperature change: j :

[0024]

[0025] According to a second aspect of the present invention, there is provided an apparatus for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate, the apparatus comprising: a waveform acquisition unit for acquiring an IGBT short-circuit current process waveform, the IGBT short-circuit current process waveform comprising a rising phase, a sustained phase and a falling phase; a first relationship acquisition unit for acquiring the control relationship of the gate voltage on the collector current in the falling phase; a second relationship acquisition unit for acquiring the relationship between the junction temperature and the electron mobility in the rising phase and the sustained phase; a third relationship acquisition unit for obtaining the relationship between the current drop rate and the junction temperature change in combination with the control relationship of the gate voltage on the collector current in the falling phase and the relationship between the junction temperature and the electron mobility in the rising phase; and a junction temperature evaluation unit for evaluating the junction temperature state of the IGBT short-circuit transient process based on the relationship between the current drop rate and the junction temperature change.

[0026] As an embodiment of the present invention, the waveform acquisition unit is specifically used to: acquire the waveforms of the gate voltage, collector-emitter voltage and collector current during the IGBT short circuit process.

[0027] As an embodiment of the present invention, the control relationship between the gate voltage and the collector current in the falling stage is shown in the following formula:

[0028]

[0029] In the above formula, i C is the collector current; μ n is the electron mobility; α pnp is the transistor transfer coefficient, which is affected by the collector-emitter voltage u CE The influence of; w is the gate channel width; l is the gate channel length; c ox is the capacitance per unit area of ​​the gate channel; u GE is the gate voltage; U T is the gate threshold voltage.

[0030] As an embodiment of the present invention, the relationship between the junction temperature and the electron mobility in the above rising stage is as follows:

[0031]

[0032] In the above formula, μ n is the electron mobility; T j is the junction temperature.

[0033] As an embodiment of the present invention, the third relationship acquisition unit is specifically used for:

[0034] The control relationship between the gate voltage and the collector current in the falling phase is derived by time derivative, and the following is obtained:

[0035]

[0036] Combining the time derivative formula and the relationship between the junction temperature and the electron mobility in the rising stage, the relationship between the current drop rate and the junction temperature change in the falling stage is obtained as follows:

[0037]

[0038] As an embodiment of the present invention, the junction temperature evaluation unit is specifically used for:

[0039] At room temperature T env At 25℃, the waveform of the current drop is recorded as i C,env ;

[0040] At junction temperature T j When the current drops, the waveform is recorded as i C,Tj ;

[0041] Through the known T env 、i C,env 、i C,Tj The junction temperature T is estimated using the following equation based on the relationship between the current drop rate and the junction temperature change: j :

[0042]

[0043] According to a third aspect of the present invention, there is provided an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0044] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0045] According to a fifth aspect of the present invention, there is provided a computer program product, comprising a computer program / instructions, which implement the steps of the above method when executed by a processor.

[0046] The method and device for evaluating the junction temperature status of the IGBT short-circuit transient process based on the current drop rate proposed in the present invention can estimate the junction temperature change of the IGBT in real time by observing the change of the short-circuit current drop rate, and provide instant temperature information. This method has guiding significance for the status monitoring and analysis of the IGBT short-circuit process, and can help engineers better understand and analyze the behavior of the IGBT under short-circuit conditions. In addition, by accurately estimating the junction temperature change, appropriate protection measures can be taken to prevent the IGBT from being damaged due to overheating, thereby improving the reliability of the system. Moreover, this method also provides a new junction temperature estimation method, which can be used to optimize the thermal management design of the IGBT and ensure that the device operates within a safe temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0048] Figure 1 It is a flow chart of a method for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate provided by an embodiment of the present invention;

[0049] Figure 2 is a schematic diagram of the commutation loop structure of a half-bridge circuit model provided by an embodiment of the present invention;

[0050] Figure 3 Schematic diagram of waveform of IGBT short-circuit transient process provided by an embodiment of the present invention;

[0051] Figure 4 It is a schematic diagram of a flow chart for obtaining the relationship between the current drop rate and the junction temperature change provided by an embodiment of the present invention;

[0052] Figure 5 It is a structural schematic diagram of a device for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate provided by an embodiment of the present invention;

[0053] Figure 6 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0055] like Figure 1 FIG. 1 is a flow chart of a method for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate provided by an embodiment of the present invention. The method comprises the following steps:

[0056] Step S101: Acquire an IGBT short-circuit current process waveform, wherein the IGBT short-circuit current process waveform includes a rising phase, a sustaining phase, and a falling phase.

[0057] Preferably, obtaining the IGBT short-circuit current process waveform in this step includes: obtaining the waveforms of the gate voltage, collector-emitter voltage and collector current during the IGBT short-circuit process.

[0058] Take a half-bridge circuit model containing IGBT as an example. Figure 2 The figure shows the commutation loop structure of the half-bridge circuit model. The circuit model should include the gate voltage (u GE )、Collector-emitter voltage(u CE )、Collector current (i C ) and other key parameters. A short-circuit condition is applied to this circuit to put the IGBT into a short-circuit state. The short-circuit condition can be controlled by controlling the gate voltage (u GE ) to make the IGBT withstand a large current in a short time. Use an oscilloscope or other high-precision measuring equipment to record the current process waveform of the IGBT in the short-circuit state. Figure 3 The waveform diagram of the IGBT short-circuit transient process is shown, which includes the following three stages:

[0059] Rising stage (t1~t2): The stage in which the short-circuit current rises rapidly from zero. During this stage, the current increases rapidly and reaches a peak value.

[0060] Sustaining stage (t2~t3): The stage in which the short-circuit current remains unchanged near the peak value. During this stage, the current remains at a higher level.

[0061] Decline phase (t3-t4): The phase where the short-circuit current starts to decrease from the peak value. During this phase, the current gradually decreases until it returns to the normal level or zero.

[0062] The recorded current process waveform data is processed and stored, and the processing process may include filtering, denoising and other steps to ensure the accuracy and availability of the data. The key time points (t1, t2, t3, t4) are marked on the recorded waveform, corresponding to the moment when the short-circuit current starts to rise, ends to rise, ends to continue, and ends to fall, respectively.

[0063] Through the above detailed steps, the complete waveform data of the IGBT short-circuit current process can be obtained, providing basic data support for the subsequent junction temperature status evaluation.

[0064] Step S102: obtaining the control relationship between the gate voltage and the collector current in the falling phase.

[0065] Determine the falling phase (t3-t4) of the short-circuit current process, that is, the time period when the short-circuit current starts to fall from the peak value. In the falling phase, use an oscilloscope or other high-precision measuring equipment to record the gate voltage (u GE ) and collector current (i C ) changes.

[0066] According to the physical characteristics and working principle of IGBT, a mathematical model of the control relationship between gate voltage and collector current is established. In this embodiment, this relationship can be expressed by the following formula (1):

[0067]

[0068] In the above formula, i C is the collector current; μ n is the electron mobility; α pnp is the transistor transport coefficient; w is the gate channel width; l is the gate channel length; c ox is the capacitance per unit area of ​​the gate channel; u GE is the gate voltage; U T is the gate threshold voltage.

[0069] Step S103: obtaining the relationship between the junction temperature and the electron mobility in the rising stage and the sustaining stage.

[0070] In the stage t1 to t3, due to the heat accumulation and temperature rise of the IGBT chip during the short circuit process, the electron mobility μ n reduce.

[0071] The junction temperature T obtained in this embodiment j and electron mobility μ n The relationship between is shown in the following formula (2):

[0072]

[0073] Wherein T is the thermodynamic temperature (unit: K). At room temperature (25°C), the thermodynamic temperature T is 273.15+25=298.15K.

[0074] Step S104: combining the control relationship between the gate voltage and the collector current in the falling phase and the relationship between the junction temperature and the electron mobility in the rising phase, to obtain the relationship between the current falling rate and the junction temperature change.

[0075] like Figure 4 As shown, this step may further include the following sub-steps:

[0076] Step S1041: performing time derivation on the control relationship between the gate voltage and the collector current in the falling phase, that is, performing time derivation on the above equation (1) to obtain the following equation (3):

[0077]

[0078] Step S1042: Combining the time derivative formula and the relationship between the junction temperature and the electron mobility in the rising stage, the relationship between the current drop rate and the junction temperature change in the falling stage is obtained, as shown in the following formula (4):

[0079]

[0080] Step S105: evaluating the junction temperature state of the IGBT short-circuit transient process based on the relationship between the current drop rate and the junction temperature change.

[0081] Preferably, this step further specifically includes:

[0082] At room temperature T env At 25℃, the waveform of the current drop is recorded as i C,env ;

[0083] At junction temperature T j When the current drops, the waveform is recorded as i C,Tj ;

[0084] Through the known T env 、i C,env 、i C,Tj The junction temperature T is estimated using the following equation (5) based on the relationship between the current drop rate and the junction temperature change: j :

[0085]

[0086] From the above, it can be seen that the method for evaluating the junction temperature state of the IGBT short-circuit transient process based on the current drop rate proposed in the present invention can estimate the junction temperature change of the IGBT in real time by observing the change of the short-circuit current drop rate, and provide instant temperature information. This method has guiding significance for the state monitoring and analysis of the IGBT short-circuit process, and can help engineers better understand and analyze the behavior of the IGBT under short-circuit conditions. In addition, by accurately estimating the junction temperature change, appropriate protective measures can be taken to prevent the IGBT from being damaged due to overheating, thereby improving the reliability of the system. Moreover, this method also provides a new junction temperature estimation method, which can be used to optimize the thermal management design of the IGBT and ensure that the device operates within a safe temperature range.

[0087] like Figure 5Shown is a schematic structural diagram of a device for evaluating the junction temperature status of an IGBT short-circuit transient process based on a current drop rate provided in the present application. The device includes: a waveform acquisition unit 510, a first relationship acquisition unit 520, a second relationship acquisition unit 530, a third relationship acquisition unit 540 and a junction temperature evaluation unit 550, which are connected in sequence.

[0088] A waveform acquisition unit 510 is used to acquire an IGBT short-circuit current process waveform, wherein the IGBT short-circuit current process waveform includes a rising phase, a sustained phase, and a falling phase;

[0089] The first relationship acquisition unit 520 is used to acquire the control relationship between the gate voltage and the collector current in the falling phase.

[0090] The second relationship acquisition unit 530 is used to acquire the relationship between the junction temperature and the electron mobility in the rising stage and the sustained stage.

[0091] The third relationship acquisition unit 540 is used to obtain the relationship between the current drop rate and the junction temperature change by combining the control relationship between the gate voltage and the collector current in the falling stage and the relationship between the junction temperature and the electron mobility in the rising stage.

[0092] The junction temperature evaluation unit 550 is used to evaluate the junction temperature state of the IGBT short-circuit transient process based on the relationship between the current drop rate and the junction temperature change.

[0093] Preferably, the waveform acquisition unit 510 is specifically used to acquire the waveforms of the gate voltage, the collector-emitter voltage and the collector current during the IGBT short circuit process.

[0094] Preferably, the control relationship between the gate voltage and the collector current in the falling stage is as follows:

[0095]

[0096] In the above formula, i C is the collector current; μ n is the electron mobility; α pnp is the transistor transport coefficient; w is the gate channel width; l is the gate channel length; c ox is the capacitance per unit area of ​​the gate channel; u GE is the gate voltage; U T is the gate threshold voltage.

[0097] Preferably, the relationship between junction temperature and electron mobility in the rising stage is as follows:

[0098]

[0099] In the above formula, μ nis the electron mobility; T j is the junction temperature.

[0100] Preferably, the third relationship acquisition unit 540 is specifically used for:

[0101] The control relationship between the gate voltage and the collector current in the falling phase is derived by time derivative, and the following is obtained:

[0102]

[0103] Combining the time derivative formula and the relationship between the junction temperature and the electron mobility in the rising stage, the relationship between the current drop rate and the junction temperature change in the falling stage is obtained as follows:

[0104]

[0105] Preferably, the junction temperature evaluation unit 550 is specifically used for:

[0106] At room temperature T env At 25℃, the waveform of the current drop is recorded as i C,env ;

[0107] At junction temperature T j When the current drops, the waveform is recorded as i C,Tj ;

[0108] Through the known T env 、i C,env 、i C,Tj The junction temperature T is estimated using the following equation based on the relationship between the current drop rate and the junction temperature change: j :

[0109]

[0110] From the above, it can be seen that the IGBT short-circuit transient process junction temperature state evaluation device proposed in the present invention can estimate the junction temperature change of the IGBT in real time by observing the change in the short-circuit current drop rate, and provide instant temperature information. This method has guiding significance for the state monitoring and analysis of the IGBT short-circuit process, and can help engineers better understand and analyze the behavior of the IGBT under short-circuit conditions. In addition, by accurately estimating the junction temperature change, appropriate protection measures can be taken to prevent the IGBT from being damaged due to overheating, thereby improving the reliability of the system. Moreover, this method also provides a new junction temperature estimation method, which can be used to optimize the thermal management design of the IGBT and ensure that the device operates within a safe temperature range.

[0111] Figure 6 is a schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 6The electronic device shown is a general data processing device, which includes a general computer hardware structure, which at least includes a processor 801 and a memory 802. The processor 801 and the memory 802 are connected via a bus 803. The memory 802 is suitable for storing one or more instructions or programs executable by the processor 801. The one or more instructions or programs are executed by the processor 801 to implement the steps in the above-mentioned IGBT short-circuit transient process junction temperature state assessment method based on the current drop rate.

[0112] The processor 801 may be an independent microprocessor or a collection of one or more microprocessors. Thus, the processor 801 executes the commands stored in the memory 802 to execute the method flow of the embodiment of the present invention as described above to realize the processing of data and the control of other devices. The bus 803 connects the above-mentioned multiple components together, and at the same time connects the above-mentioned components to the display controller 804 and the display device and the input / output (I / O) device 805. The input / output (I / O) device 805 may be a mouse, a keyboard, a modem, a network interface, a touch input device, a somatosensory input device, a printer, and other devices known in the art. Typically, the input / output (I / O) device 805 is connected to the system via an input / output (I / O) controller 806.

[0113] The memory 802 may store software components such as an operating system, a communication module, an interaction module, and an application program. Each of the modules and applications described above corresponds to a set of executable program instructions that implement one or more functions and methods described in the embodiments of the invention.

[0114] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned method for evaluating the junction temperature state of an IGBT short-circuit transient process based on the current drop rate.

[0115] An embodiment of the present invention further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned method for evaluating the junction temperature state of an IGBT short-circuit transient process based on the current drop rate.

[0116] From the above, it can be seen that the method and device for evaluating the junction temperature state of the IGBT short-circuit transient process based on the current drop rate proposed in the present invention can estimate the junction temperature change of the IGBT in real time by observing the change of the short-circuit current drop rate, and provide instant temperature information. This method has guiding significance for the state monitoring and analysis of the IGBT short-circuit process, and can help engineers better understand and analyze the behavior of the IGBT under short-circuit conditions. In addition, by accurately estimating the junction temperature change, appropriate protection measures can be taken to prevent the IGBT from being damaged due to overheating, thereby improving the reliability of the system. Moreover, this method also provides a new junction temperature estimation method, which can be used to optimize the thermal management design of the IGBT and ensure that the device operates within a safe temperature range.

[0117] The preferred embodiments of the present invention are described above with reference to the accompanying drawings. Many features and advantages of these embodiments are clear from this detailed description, and therefore the claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and changes are easily conceivable to those skilled in the art, it is not intended to limit the embodiments of the present invention to the precise structure and operation illustrated and described, but all suitable modifications and equivalents falling within its scope may be covered.

[0118] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0119] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0120] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0121] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0122] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for evaluating the junction temperature state of an IGBT short-circuit transient process based on a current drop rate, characterized in that: The method comprises: Acquire an IGBT short-circuit current process waveform, wherein the IGBT short-circuit current process waveform includes a rising phase, a sustained phase, and a falling phase; Obtaining the control relationship between the gate voltage and the collector current in the falling phase; Obtaining the relationship between the junction temperature and the electron mobility in the rising stage and the sustained stage; Combining the control relationship between the gate voltage and the collector current in the falling stage and the relationship between the junction temperature and the electron mobility in the rising stage, the relationship between the current falling rate and the junction temperature change is obtained; The junction temperature state of the IGBT short-circuit transient process is evaluated based on the relationship between the current drop rate and the junction temperature change.

2. The method for evaluating the junction temperature status of an IGBT short-circuit transient process based on the current drop rate according to claim 1, characterized in that: The process of obtaining the IGBT short-circuit current waveform includes: Obtain the waveforms of gate voltage, collector-emitter voltage and collector current during IGBT short circuit.

3. The method for evaluating the junction temperature status of an IGBT short-circuit transient process based on the current drop rate according to claim 1, characterized in that: The control relationship between the gate voltage and the collector current in the falling stage is shown in the following formula: In the above formula, i C is the collector current; μ n is the electron mobility; α pnp is the transistor transport coefficient; w is the gate channel width; l is the gate channel length; c ox is the capacitance per unit area of ​​the gate channel; u GE is the gate voltage; U T is the gate threshold voltage.

4. The method for evaluating the junction temperature status of an IGBT short-circuit transient process based on the current drop rate according to claim 3, characterized in that: The relationship between junction temperature and electron mobility during the ramp-up phase is as follows: In the above formula, μ n is the electron mobility; T j is the junction temperature.

5. The method for evaluating junction temperature status of an IGBT short-circuit transient process based on current drop rate according to claim 4, characterized in that: The relationship between the current drop rate and the junction temperature change obtained by combining the control relationship between the gate voltage and the collector current in the falling stage and the relationship between the junction temperature and the electron mobility in the rising stage includes: The control relationship between the gate voltage and the collector current in the falling phase is derived by time derivative, and the following is obtained: Combining the time derivative formula and the relationship between the junction temperature and the electron mobility in the rising stage, the relationship between the current drop rate and the junction temperature change in the falling stage is obtained as follows:

6. The method for evaluating junction temperature status of an IGBT short-circuit transient process based on current drop rate according to claim 5, characterized in that: The evaluation of the junction temperature state of the IGBT short-circuit transient process based on the relationship between the current drop rate and the junction temperature change includes: At room temperature T env At 25℃, the waveform of the current drop is recorded as i C,env ; At junction temperature T j When the current drops, the waveform is recorded as i C,Tj ; Through the known T env 、i C,env 、i C,Tj The junction temperature T is estimated using the following equation based on the relationship between the current drop rate and the junction temperature change: j :

7. A device for evaluating the junction temperature status of an IGBT short-circuit transient process based on a current drop rate, characterized in that: The device comprises: A waveform acquisition unit, used to acquire an IGBT short-circuit current process waveform, wherein the IGBT short-circuit current process waveform includes a rising phase, a sustained phase, and a falling phase; A first relationship acquisition unit, used to acquire the control relationship between the gate voltage and the collector current in the falling stage; A second relationship acquisition unit is used to acquire the relationship between the junction temperature and the electron mobility in the rising stage and the sustained stage; A third relationship acquisition unit is used to obtain the relationship between the current drop rate and the junction temperature change by combining the control relationship between the gate voltage and the collector current in the falling stage and the relationship between the junction temperature and the electron mobility in the rising stage; The junction temperature evaluation unit is used to evaluate the junction temperature state of the IGBT short-circuit transient process based on the relationship between the current drop rate and the junction temperature change.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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